Dimethylformamide → dimethyl(2S,3S,5S)-5-hydroxy-2-[(4-phenylpiperazin-1-yl)carbonyl]piperidine-1,3-dicarboxylate

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Reaction Steps

To a mixture of (2S,3S,5S)-5-hydroxy-3-(methoxycarbonyl)piperidine-2-carboxylic acid (1.10 g, 0.00541 mol), 1-phenyl-piperazine, (0.910 mL, 0.00595 mol) and benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (2.63 g, 0.00595 mol) in N,N-dimethylformamide (6.00 mL, 0.0775 mol) was added N,N-diisopropylethylamine (1.04 mL, 0.00595 mol) at 0 Celsius. The reaction was stirred at rt for 3 h. To the reaction mixture was added methylene chloride (40.00 mL, 0.6240 mol), cat. amount of DMAP, N,N-diisopropylethylamine (2.36 mL, 0.0135 mol), followed by methyl chloroformate (0.836 mL, 0.0108 mol) at 0 Celsius. The resulting reaction mixture was stirred at rt overnight. After quenched with water, the mixture was extracted with ethyl acetate. The combined organic layers were washed with brine, dried and concentrated to dry. The residue was purified on silica gel, eluting with 0 to 100% EtOAc in hexane, to give the titled compound (1.88 g, 85.7%). MS (ESI): (M+H)+=406.2.

Provenance & Evidence